The present invention relates to a disc turnover device, and, more particularly, to a device for lifting a flat disc from a continuously moving conveyor, turning the disc over and placing it back on the conveyor.
There has been recently developed a high density recorded disc, i.e. a video disc, in which the recorded information is in the form of a surface relief pattern formed along a spiral path on both major surfaces of the disc. The recorded disc is played back with a stylus that senses the information capacitively. In order to reduce friction and to prevent wear of the stylus and/or the disc during playback, a very thin layer, perferably between 200 and 400 Angstroms thick, of a lubricant is provided on the surface of the disc.
One apparatus for coating a disc with a thin layer of a lubricant is shown and described in U.S. Pat. No. 4,424,761 of J. H. Thorn et al., filed Sept. 30, 1982, entitled "Nozzle for Coating a Disc with a Lubricant." In this apparatus, the disc is carried in a flat horizontal position on a horizontally /moving conveyor through a coating chamber where the lubricant is directed downwardly onto the surface of the disc. However, to coat both sides of the disc, it is necessary to turn the disc over and pass it through another coating chamber where lubricant is applied to the second side of the disc. For such a coating system it is desirable to have a device which lifts the disc from the continuously moving conveyor, turns the disc over and then places the disc back on the conveyor.